java.lang.Object
- jakarta.persistence.spi.PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver

All Implemented Interfaces:

PersistenceProviderResolver

Enclosing class:

PersistenceProviderResolverHolder
```
private static class PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver
extends java.lang.Object
implements PersistenceProviderResolver
```
Default provider resolver class to use when none is explicitly set.
Uses service loading mechanism as described in the Jakarta Persistence specification. A ServiceLoader.load() call is made with the current context classloader to find the service provider files on the classpath.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`private class`	`PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.CacheKey`	Key used for cached persistence providers.
`private static interface`	`PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.CacheKeyReference`	The common interface to get a CacheKey implemented by LoaderReference and PersistenceProviderReference.
`private class`	`PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.LoaderReference`	References to class loaders are weak references, so that they can be garbage collected when nobody else is using them.
`private class`	`PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.PersistenceProviderReference`	References to persistence provider are soft references so that they can be garbage collected when they have no hard references.

Field Summary

Fields
Modifier and Type	Field	Description
`private java.util.logging.Logger`	`logger`
`private static java.lang.String`	`LOGGER_SUBSYSTEM`
`private java.util.HashMap<PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.CacheKey,PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.PersistenceProviderReference>`	`providers`	Cached list of available providers cached by CacheKey to ensure there is not potential for provider visibility issues.
`private static java.lang.ref.ReferenceQueue`	`referenceQueue`	Queue for reference objects referring to class loaders or persistence providers.

Constructor Summary

Constructors
Modifier Constructor Description

private DefaultPersistenceProviderResolver()

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`clearCachedProviders()`	Clear all cached providers
`private static java.lang.ClassLoader`	`getContextClassLoader()`	Wraps `Thread.currentThread().getContextClassLoader()` into a doPrivileged block if security manager is present
`java.util.List<PersistenceProvider>`	`getPersistenceProviders()`	Returns a list of the persistence provider implementations available in the runtime environment.
`private void`	`log(java.util.logging.Level level, java.lang.String message)`
`private void`	`processQueue()`	Remove garbage collected cache keys & providers.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - providers
```
private volatile java.util.HashMap<PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.CacheKey,PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.PersistenceProviderReference> providers
```
    Cached list of available providers cached by CacheKey to ensure there is not potential for provider visibility issues.
  - referenceQueue
```
private static final java.lang.ref.ReferenceQueue referenceQueue
```
    Queue for reference objects referring to class loaders or persistence providers.
  - LOGGER_SUBSYSTEM
```
private static final java.lang.String LOGGER_SUBSYSTEM
```
    See Also:
    
    Constant Field Values
  - logger
```
private java.util.logging.Logger logger
```
- Constructor Detail
  - DefaultPersistenceProviderResolver
```
private DefaultPersistenceProviderResolver()
```
- Method Detail
  - getPersistenceProviders
```
public java.util.List<PersistenceProvider> getPersistenceProviders()
```
    Description copied from interface: PersistenceProviderResolver
    
    Returns a list of the persistence provider implementations available in the runtime environment.
    
    Specified by:
    
    getPersistenceProviders in interface PersistenceProviderResolver
    
    Returns:
    
    list of the persistence providers available in the environment
  - processQueue
```
private void processQueue()
```
    Remove garbage collected cache keys & providers.
  - getContextClassLoader
```
private static java.lang.ClassLoader getContextClassLoader()
```
    Wraps Thread.currentThread().getContextClassLoader() into a doPrivileged block if security manager is present
  - log
```
private void log(java.util.logging.Level level,
                 java.lang.String message)
```
  - clearCachedProviders
```
public void clearCachedProviders()
```
    Clear all cached providers
    
    Specified by:
    
    clearCachedProviders in interface PersistenceProviderResolver

Class PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

providers

referenceQueue

LOGGER_SUBSYSTEM

logger

Constructor Detail

DefaultPersistenceProviderResolver

Method Detail

getPersistenceProviders

processQueue

getContextClassLoader

log

clearCachedProviders